Collmenter emerged as a starter on the D-backs’ 2011 NL West championship team, but has found a more permanent and valuable role as a swing man in the bullpen. But with the struggles of the D-backs’ starters — they’ve combined for an ERA over six, and Delgado sports a 10.13 ERA — Collmenter will likely prove more valuable in the rotation.

“We need innings out of guys that give us a chance to win the ball game,” Gibson said. “Just looking at our options, we think it’s the smartest way to go.”

Collmenter will start on Monday against the New York Mets, while Bronson Arroyo will get an extra day of rest and pitch on Tuesday. Collmenter has a 2.25 ERA in eight innings of relief this season.